Implementing format strings for filename counts on multisaves

lib/squib/api/save.rb

@@ -25,14 +25,15 @@ module Squib
     # @option opts [Enumerable] range (:all) the range of cards over which this will be rendered. See {file:README.md#Specifying_Ranges Specifying Ranges}
     # @option opts [String] dir (_output) the directory for the output to be sent to. Will be created if it doesn't exist.
     # @option opts [String] prefix (card_) the prefix of the file name to be printed.
+    # @option opts [String] count_format (%02d) the format string used for formatting the card count (e.g. padding zeros). Uses a Ruby format string (see the Ruby doc for Kernel::sprintf for specifics)
     # @option opts [Boolean, :clockwise, :counterclockwise] rotate (false) if true, the saved cards will be rotated 90 degrees clockwise. Or, rotate by the number of radians. Intended to rendering landscape instead of portrait.
     # @return [nil] Returns nothing
     # @api public
     def save_png(opts = {})
-      opts = needs(opts,[:range, :creatable_dir, :prefix, :rotate])
+      opts = needs(opts,[:range, :creatable_dir, :prefix, :count_format, :rotate])
       @progress_bar.start("Saving PNGs to #{opts[:dir]}/#{opts[:prefix]}*", @cards.size) do |bar|
         opts[:range].each do |i|
-          @cards[i].save_png(i, opts[:dir], opts[:prefix], opts[:rotate], opts[:angle])
+          @cards[i].save_png(i, opts[:dir], opts[:prefix], opts[:count_format], opts[:rotate], opts[:angle])
           bar.increment
         end
       end

lib/squib/constants.rb

@@ -9,6 +9,7 @@ module Squib
       :blend => :none,
       :color => :black,
       :columns => 1,
+      :count_format => '%02d',
       :default_font => 'Arial 36',
       :dir => '_output',
       :ellipsize => :end,

lib/squib/graphics/save_doc.rb

@@ -49,6 +49,7 @@ module Squib
     # @option opts colulmns [Integer] (1) the number of columns in the grid
     # @option opts rows [Integer] (:infinite) the number of rows in the grid. When set to :infinite, the sheet scales to the rows needed. If there are more cards than rows*columns, new sheets are started.
     # @option opts [String] prefix (card_) the prefix of the file name(s)
+    # @option opts [String] count_format (%02d) the format string used for formatting the card count (e.g. padding zeros). Uses a Ruby format string (see the Ruby doc for Kernel::sprintf for specifics)
     # @option opts dir [String] (_output) the directory to save to. Created if it doesn't exist.
     # @option opts margin [Integer] (0) the margin around the outside of the page
     # @option opts gap [Integer] (0) the space in pixels between the cards
@@ -57,7 +58,7 @@ module Squib
     # @api public
     def save_sheet(opts = {})
       opts = {margin: 0}.merge(opts) # overriding the non-system default
-      p = needs(opts, [:range, :prefix, :creatable_dir, :margin, :gap, :trim, :rows, :columns])
+      p = needs(opts, [:range, :prefix, :count_format, :creatable_dir, :margin, :gap, :trim, :rows, :columns])
       # EXTRACT METHOD HERE
       sheet_width = (p[:columns] * (@width + 2 * p[:gap] - 2 * p[:trim])) + (2 * p[:margin])
       sheet_height = (p[:rows] * (@height + 2 * p[:gap] - 2 * p[:trim])) + (2 * p[:margin])
@@ -68,7 +69,8 @@ module Squib
       @progress_bar.start("Saving PNG sheet to #{p[:dir]}/#{p[:prefix]}_*", @cards.size + 1) do |bar|
         p[:range].each do |i|
           if num_this_sheet >= (p[:columns] * p[:rows]) # new sheet
-            cc.target.write_to_png("#{p[:dir]}/#{p[:prefix]}#{sheet_num}.png")
+            filename = "#{p[:dir]}/#{p[:prefix]}#{p[:count_format] % sheet_num}.png"
+            cc.target.write_to_png(filename)
             new_sheet = false
             num_this_sheet = 0
             sheet_num += 1
@@ -87,7 +89,7 @@ module Squib
           end
           bar.increment
         end
-        cc.target.write_to_png("#{p[:dir]}/#{p[:prefix]}#{sheet_num}.png")
+        cc.target.write_to_png("#{p[:dir]}/#{p[:prefix]}#{p[:count_format] % sheet_num}.png")
       end
     end
 

lib/squib/graphics/save_images.rb

@@ -3,13 +3,13 @@ module Squib
 
     # :nodoc:
     # @api private
-    def save_png(i, dir, prefix, do_rotate, angle)
+    def save_png(i, dir, prefix, count_format, do_rotate, angle)
       if [true, :clockwise, :counterclockwise].include?(do_rotate)
         surface = rotated_image(angle)
       else
         surface = @cairo_surface
       end
-      write_png(surface, i, dir, prefix)
+      write_png(surface, i, dir, prefix, count_format)
     end
 
     # :nodoc:
@@ -25,8 +25,8 @@ module Squib
     end
     # :nodoc:
     # @api private
-    def write_png(surface, i, dir, prefix)
-      surface.write_to_png("#{dir}/#{prefix}#{i}.png")
+    def write_png(surface, i, dir, prefix, count_format)
+      surface.write_to_png("#{dir}/#{prefix}#{count_format % i}.png")
     end
 
   end